Author Topic: Goal for Distance Vision  (Read 1092 times)

Offline VisionRecovery

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Goal for Distance Vision
« on: July 19, 2015, 06:59:30 PM »
What should be the goal at which we are done improving our distance vision?

If the edge of focus is at 50 cm with +2 reading glasses, then you have a refractive state of 0.0 diopters and you are emmetropic.

If we "overdo" it and the edge of focus is at 57 cm with a +2 D lens, wouldn't we have a refractive state of +0.25 D and be hyperopic?

Offline VisionRecovery

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Re: Goal for Distance Vision
« Reply #1 on: July 19, 2015, 08:19:54 PM »
Otis,

Let's consider an eye whose refractive state is 0.0 D (as HansK defines it). Then it appears that changing it to +0.25 D would have no effect on distance visual acuity, but it would affect near vision.

When presbyopia occurs in the future, with 2.0 D of accommodation, the 0.0 D eye can see between 50 cm and infinity, while the +0.25 D eye can see between 57 cm and infinity. Then wouldn't 0.25 D of accommodation be "wasted"?

0.0 D would be "normal" and +0.25 D seems to be "farsighted" in this diagram: http://hyperphysics.phy-astr.gsu.edu/hbase/vision/accom2.html
« Last Edit: July 19, 2015, 08:25:50 PM by VisionRecovery »